1. Field of the Invention:
The present invention relates generally to a system and method for automated, rapid, safe and effective delivery of drugs into the circulatory system. More particularly, it relates to such a system and method in which the drugs are delivered by infusion directly into the red marrow of the adult sternum or the pediatric tibia.
2. Description of the Prior Art
There is a critical need for better and more rapid methods of vascular delivery of drugs. The development of new, life saving drugs and better knowledge of how specific drugs work has established that many drugs can prevent death or reduce morbidity if given in a timely manner. Unfortunately, most drugs need to be infused directly into the blood of the general circulation to be effective, and this is not always easily accomplished. Vascular injections and cannulations are procedures requiring professional skills and training that are usually only possessed by doctors, nurses and paramedics. Even these professionals have a significant failure rate and generate time delays for drug delivery in emergency conditions, when veins are often collapsed due to low blood pressure, and several procedures need to be accomplished as soon as possible. Many other professionals and lay personnel, such as flight attendants, police, life guards and teachers, are trained in advanced first aid and cardiopulmonary resuscitation (CPR), but can not deliver drugs, due to lack of an effective method that does not require more medical training. Clearly, there is a need for a simple, better and more rapid means of drug delivery to aid both skilled professionals and para-professionals to expand the utility of life saving drugs.
It has long been known that the red marrow sinuses of bones are virtual non-collapsible veins. Fluids and drugs have been shown to enter the central circulation after intraosseous (IO) infusions as rapidly or even more rapidly than peripheral vein infusions. This IO method can be used to deliver drugs via the long bones of children, but in adults, only the sternum and bones of the pelvic girdle contain large red marrow spaces. Intraosseous infusions are well known and often used in children, but less well utilized in adults. However, most medical emergencies occur in adults.
Many special needles and devices have been made both to sample marrow and to infuse into the red marrow. All of these needles require substantial training and skill for their correct and safe use and take several seconds to minutes to use them properly. Examples of such prior art devices are disclosed in U.S. Pat. Nos. 2,426,535, issued Aug. 26, 1947 to Turkel; 2,773,500, issued Jan. 26, 1955 to Young; 3,750,667, issued Aug. 7, 1973 to Pshenichny et al; 4,969,870, issued Nov. 13, 1990 to Kramer et al., and in the following articles: Tocantins, L. M. and O'Neill, J. F., "Infusion of Blood and Other Fluids into the General Circulation Via the Bone Marrow," Surg. Gynecol. Obstet., 73, 281-287 (1941); Turkel, H. and Bethell, F. H., "A New and Simple Instrument for Administration of Fluids Through Bone Marrow," War Medicine, 5, 222-225 (1944); Glaeser, P. W. and Losek, J. D. "Intraosseous Needles: New and lmproved,38 Pediat. Emerg. Care, 4, 135-136 (1989); Sacchetti, A. D., Linkenheimer, R., Lieberman, M., Haviland, P., Kryszozak, L. B., "Intraosseous Drug Administration: Successful Resuscitation from Asystole," Pediat. Emerg. Care, 5, 97-98 (1989); Halvorsen, L., Bay, B. K., Perron, P. R. Gunther, R. A., Holcroft, J. W., Blaisdell, F. W., Kramer, G. C., "Evaluation of an Intraosseous Infusion Device for the Resuscitation of Hypovolemic Shock," J. Traum., 30, 652-659 (1990). The above references describe manually inserted needles and techniques which require skill and training for proper use and necessitate many seconds to minutes in use. An automated needle system for delivery of drugs into the red marrow would have great utility.
A variety of auto-injection syringes for intramuscular or subcutaneous injections are also known in the art. Examples of such syringes are disclosed in the following U.S. Pat. Nos.: 3,396,726, issued Aug. 13, 1968 to Sarnoff; 3,712,301, issued Jan. 23, 1973 to Sarnoff; 3,882,863, issued May 13, 1975 to Sarnoff et al.; 4,031,893, issued Jun. 28, 1977 to Kaplan et al. However, these syringes are not designed, nor could they be effectively or safely used for injecting into the red marrow sinuses of bones, nor do they prevent needles used in the procedures from being exposed so that there is a danger of accidental needle punctures in use of these syringes.